Iontophoresis is widely accepted procedure used primarily in medical practices and physical therapy settings for the delivery and electro-transport of various medicaments through the skin. The medicaments can include anesthetic solutions or gels and anti-inflammatory solutions or gels, among others.
Iontophoresis uses electrical current to drive polarized solutions (positive and negative). Positively charged solutions/gels/semi-solids are repelled by positive poles and attracted by negative poles, and vice versa, to complete a circuit. The drugs are forced across the skin by electronic repulsion of similar charges. Anionic medicaments may be pushed through the skin by using a negatively charged electrode and cationic medicaments may be pushed through the skin using a positively charged electrode. When used on skin, commonly, a positive solution is placed on a positively charged electrode. A negatively charged electrode is placed at an alternative site on the body and serves as a ground for the circuit. Thus, iontophoresis is the facilitated movement of ions across a membrane under the influence of an externally applied small electrical potential difference. Iontophoresis is localized, non-invasive, convenient and a rapid method of delivering ionized medicament.
Iontophoresis is one approach for delivering drugs as well as therapeutic proteins, peptides, and oligonucleotides. The advantages of iontophoresis are numerous and well known in the art, including improved therapeutic efficacy due to a bypass of hepatic metabolism and the use of drugs with short biological half life due to the direct delivery to the target area. A further advantage is that iontophoresis is a non-invasive method to systematically administer a small amount of drug. Some of the commercially available iontophoretic delivery systems include LIDOSITE, a system to deliver lidocaine and Iomed PHORESOR for the delivery of botulinum.